Actually I just figured it out!
It’s not the page ID as in the permalink id but the actual numerical id. So if a post or page is number 66 (find by hovering over the page/post in edit) you put that into your exclude in settings.
I’m having the same problem.
When I actually enter something into the exclude page/post section, it just disappears. I have tried it with a comma after, no comma, different spellings and random posts and no luck.
It says Settings saved as well.
